Models and Biomarkers for Ovarian Ageing

The human ovarian reserve is defined by the number of non-growing follicles (NGFs) in the ovary, with the age-related decline in NGF population determining age at menopause for healthy women. In this chapter, the concept of ovarian reserve is explored in detail, with a sequence of models described that in principle allow any individual to be compared to the general population. As there is no current technology that can count the NGFs in a living ovary, we move our focus to biomarkers for the ovarian reserve. Using serum analysis and ultrasound it is possible to measure anti-Müllerian hormone (AMH), follicle-stimulating hormone (FSH), and ovarian volume (OV) and to count numbers of antral follicles (AFC). These are compared, with ovarian volume being the closest to a true biomarker for a wide range of ages and with AMH and AFC being the most popular for post-pubertal and pre-menopausal ages. The study of genetic and subcellular biomarkers for the ovarian reserve has produced less concrete results. Recent advances are described and compared in terms of limitations and potential. The chapter concludes with an overview of the future study indicated by our current knowledge and by current controversy in the field.